There is a story to these pictures, if you are wondering what the growth is called, it is referred to as “pipe tuberculation” or “insoluble corrosion residue buildup” and the main issue is that it increases pipe friction losses thus reducing fire flows, but can also ultimately lead to pipe failure. The infrastructure in many of Canada’s cities is failing. This is an example of a pipe that until yesterday was still in service eighty years after it was installed, it has spent it’s life providing water to thousands of residents and aside from annual hydrant flushing, would have received no special treatment – much like every other watermain in every other city in North America. It is interesting to note that some of the technologies that are available to postpone the replacement of pipes in this condition, such as watermain pigging, are still considered relatively novel, and when a pipe is in this condition, money spent on pigging it may be better spent on funding the replacement of it, depending on other factors such as the condition of the road surface and the adequacy of the watermain size.

There is a lot to say about how the infrastructure of North America got to this point and what it will take to fix it, but that is for another post.

If you are interested in the chemical processes that cause this type of corrosion, check out this page on the Fire Protection Engineering Archives.

This post was written by Mike Thomas for UrbanWorkbench.com ©2010.

Originally posted as 80 Year Old Watermain

Technorati Tags: Business, Canada, Corrosion, pipe tuberculation, Rossland, Site Construction, tuberculation, Water, water pipe, Water supply network, water utility, watermain

Clean water is something that most of my readers probably quite happily take for granted. Despite the fact that in most Cities the systems we use to clean and transport water are among some of the most decrepit parts of the infrastructure of the communities we live in, we assume that when we turn on the tap, clean water will be available immediately.

Watch the 10 minute video below and learn something about the economic and health realities of dirty water. While the bulk of the video presentation is about the third world applications of this invention, disaster applications are mentioned, including the issues after Hurricane Katrina.

Would you spend $180 for the security of having access to up to 6000L of clean potable water for your family in an emergency? The device has a shelf life of 3 years unopened and can be used for up to 5 years after that if maintained properly. At $5 a month for three years, it is a pretty good insurance investment against disaster.

In our house we have several gallon jugs of water down in the cold room for an emergency, but aside from that, we are almost entirely dependent on the continuity of the City water supply for all of our water needs and wants.

These guys do have a US distributor, (who does ship to Canada for phone orders).

This post was written by Mike Thomas for UrbanWorkbench.com ©2010.

Originally posted as The Lifesaver Bottle

Technorati Tags: clean water, dirty water, disaster management, disease, engineering, Hurrucane Katrina, lifesaver bottle, pollution, third world, Water, water purification, water security, Water Supply

If you want to get a picture of the last twenty or thirty years of the oil industry, then Oil – Money, Politics, and Power in the 21st Century by Tom Bower is a must read.

Released in June 2010, it just missed out on recording one of the biggest oil related disasters, the Deep Water Horizon blowout in the Gulf of Mexico under BPs watch, but paints a clear picture of the forces behind this catastrophic events from trading squeezes, nationalization of oil companies, interference from western governments, taxes, and the personalities of the men (because it has been an almost exclusive club of men) that run the big oil companies.

Pitched as a sequel to The Prize by Daniel Yurgin, “Oil” follows the lives of the biggest players in oil on all sides of the industry. A mix between current affairs and history, it is obvious that Bower has some excellent sources within the oil companies, telling the story from as many sides as possible. The details of deals, politics and price-fixing make you wonder if we will ever again see a realistic price for oil and it’s products.

But that leads me to my one complaint, the discussions about Peak Oil have a fairly patronizing tone. This would be acceptable if the premise of Peak Oil had absolutely no merit, but whether a peak is today or in 100 years time, the issue is not one that is just going to disappear. And if this is the case, should we be attempting to conserve oil rather than waste it, and what would a conservation pricing structure look like?

The Canadian tar sands are given a brief discussion, as is the Exxon Valdez spill among other disasters, Interestingly, the book showed me that investing in oil is a fickle game, challenging the idea that the price of oil will always go up, so investing in it is a no-lose proposition. Overall the book provides an insight into a world that most people have little knowledge about, and for that I’d strongly recommend it as a resource for those wishing to learn more about it, but beyond that it provides little hope for the future in terms of climate change, peak oil or resource wars – it really just shows how excessively greedy man is and how ignorant of the long-term consequences all of us are of our actions.

Reviewed from an Advanced Reading Copy provided by Hachette Book Group (thanks!)

This post was written by Mike Thomas for UrbanWorkbench.com ©2010.

Originally posted as The Story of Oil in the 21st Century

Technorati Tags: Business, climate change, Energy, environment, Gulf of Mexico, Oil and Gas, peak oil, Petroleum industry

Jude stood on the simple wooden train platform, it was just long enough to accommodate a family of four, and just high enough to allow a father to hoist his children into the carriage doorway. Little more was needed, these days there weren’t more than a handful of families living in this remote extension of the community. His late father used to tell the story of his daddy buying the house there, how he told of the salesmen in their open-collar shirts with gold chains, wearing golf shoes had promised the world to families and retired couples. Jude remembered asking his father what “retired” meant.

His father had chuckled and said, “‘Retired’ is what people who thought they’d worked hard enough in their life did when they wanted to holiday for the rest of their lives”.

“So why aren’t you retired dad?” he remembered asking, still blushing at the insensitivity of his teenage inquisition of his father.

“Well son, in those days making money didn’t take work, it took luck, and if you were lucky, you could live off the money you made for twenty years or more. You could tell someone to invest your money in a company in China, and they would just make it happen, all with a few clicks on the computer, you didn’t even need to see the money or go to the bank to withdraw it”. The memory faded as he considered the blessings of his own little family, things were mighty different from when he was a boy – hardship was commonplace these days, life was just tougher and so were the people. His father was long gone, but the memories of watching this strong man work with his hands made Jude proud to be his son.

He turned his head as he heard the train whistle down the line, gathering up his pull cart, ensuring that the bags containing the produce were strapped down in the bed. “Not so bad”, he thought to himself, “only had to wait a couple of hours this time”. Today’s trip into town would be the first for the summer, his wife Ella and the children would stay home this time, there was still much work to be done around the homestead. He waved to the driver as the engine came into view, and heard the squeal of the brakes as the clickity-clack slowed to a walking pace, carriages whipping past in a blur of windows and faces. The conductor appeared at a door that stopped in front of the platform. They negotiated a price for the ride, this was a privately operated train on a railway that no longer received any attention from CPR. Instead a group of train owners employed local labour a couple of times a year to perform rudimentary maintenance to the track and right of way. It was an arrangement that had served the local population well for over a decade, it seemed unlikely that CPR would be back to claim their line any time soon.

The conductor helped him with the cart and he made his way to find a seat in the carriage’s interior as the train started again with a hiss of steam and a loud blow of the whistle. Jude’s senses were assaulted as the compartment door slammed behind him. A few faces turned his was to see who the newcomer was,  but most remained focussed on their goods, or the conversation with their travel partners. First it was the smell, in one corner of the compartment, where the original designers had likely imagined long distance travellers placing their luggage for the duration of the journey, sat four very large pigs.

Some of the bridges between his stop and the town were obviously in bad shape, requiring the train to slow down to a crawl. Jude offered a silent prayer as his carriage made the precarious crossing, was it his imagination or could he hear the groans of the steel and timber members under the load of each wheel? He furtively looked around the carriage and could see some of the occupants engaged in similar upward-looking supplications to an unseen deity, apparently he wasn’t alone in his distrust of the maintenance capabilities of the Kootenay Railway Company. As the last wheels of the train passed from bridge to land, a collective sign of relief shifted the air within the carriage, at least Jude hoped that was the case-  it was that, or the pigs had passed wind.

The whistle blasted out a mournful sound as they slowed, coming round the last corner into town. In his lifetime, the downtown had shrunk to what was manageable on your own two feet, most everything else had fallen to the wayside – not just because of transportation options for residents, but because there wasn’t enough stuff to sell, or money to buy it anymore either. The gas stations were gone, the car yards were cracked and full of noxious weeds, the buildings long abandoned. The railway was the last surviving safe link between the communities of this valley. Jude saw the new church across the way, he couldn’t remember what had been there before, some nondescript strip mall or warehouse-style big box store he guessed. At last the train shuddered to a stop, the momentum of each carriage fighting the couplings in a wave of noise and motion and the release of steam billowing out across the platform,the station master checking the arrival time on his pocket watch as though he was at Grand Central – it was not as though there was any other train expected to require the services of the platform today, however, it was the motions of a man who knew what was expected of him in his appointed position, even if the train was over two hours late.

Jude waited for the rush of people and animals to leave the carriage, collected his cart, made sure the bags of produce were secured. He marveled at the people, it had been almost two months since his first trip for the year, and it felt good to be back in town. He paused in the shade of the platform awning planning out his day, based on the errands he had to run and the meager handful of cash and coins he had in his pocket. First he would head down to the barbershop, a shave and a haircut were a luxury, but it was a necessary part of the journey to find out what’s making the news these days. Then he would swing by the general store for household supplies, the list that Ella had carefully written out was safely in his breast pocket, he’d checked it over as he waited for the train: cloth, needles, teapot, candles, sugar and salt; while he was there he’d pick out some candies for the children and search for a gift for Ella. The market would be the next stop, he needed to sell the carrots, beets, radishes and peas that were the excess from his first harvest, and hopefully pick up some early tomatoes as a surprise. The cobber was on his list – he looked down at the hole in his boot, he knew he had to get it fixed, or he would have to replace it soon enough. The stock yards would have quietened down by the time he got round there, he prayed that there would be some turkey chicks for sale and maybe a pig or two, there were a few birthdays coming up and Jude wanted to raise some fine animals for the celebrations.

He smiled to himself as he thought of the stories his father once told him, how people used to shop for fun, that they replaced games and family time with buying more stuff than they had room for in their houses. Today would be a good day, it was as much work as any of the other days of his life, but he knew the seasons bring new challenges and blessings, selling produce was a blessing. With a small hop, he shouldered the rope used to pull the cart and made his way off the station platform and into the bustle of downtown, he would be back to ride the train home tomorrow morning.

This post was written by Mike Thomas for UrbanWorkbench.com ©2010.

Originally posted as Peak Oil Vignette 6 – A Trip into Town

Technorati Tags: Big-box store, Columbia, fiction, Kootenay, peak oil, Rail transport, Railway platform, Train, Trains and Railroads

This time of year makes for some magical photos around the Kootenays. This is the Brilliant Dam and Generating Stations on the Kootenay River taken from HWY 3A just outside of Castlegar on the road to Nelson, BC.

We often stop here with the kids to watch the memorizing flow of water over the spillway. When Mom and Dad are both Civil Engineers, it is highly likely that children will be subjected to an impromptu home-school lesson on hydro-electric power generation, gravity, potential energy, concrete construction techniques or any other dam related topic. Yes, I am an engineer.

This post was written by Mike Thomas for UrbanWorkbench.com ©2010.

Originally posted as Spring Freshet at Brilliant Dam

Technorati Tags: British Columbia, Castlegar British Columbia, Electricity generation, Hydroelectricity, Hydropower, Kootenay River, Kootenays, Nelson British Columbia

Writing is part of my daily routine, I write a lot, both for work and for myself. Being an engineer and a writer seems to be a contradiction to most people, as though the hard analytical mind of an engineer can simply not operate in a creative endeavor such as writing. I’ll share a secret – my mind is not the typical rigorously analytical, process-driven computer that people expect to it to be. Instead, I see myself as part of the Creative Class – a thinker, a problem-solver, as much a “social” engineer as a civil engineer.

The role of engineers in society is slowly moving away from a narrow focus of building stuff and toward a recognition of engineers as having value outside of the traditional realms. Writing puts a human face to what I do every day. The ability to tell a story and share my point of view, removed from the technical constraints and other anti-social aspects of engineering, is truly liberating. My experiences have spanned several countries, many areas of practice with roles in sectors such as development, water, sewer, urban planning, mining, transportation, environmental, materials, military, emergency and municipal. These experiences give me a different perspective from many on the issues that face our towns, countries and the world we live in. I am not a traditional engineer, sure, there is plenty of need for engineers to design roads, buildings and other works and products. Sometimes that’s me too, but mostly, I’m working to improve the sustainability of where we live in the long run, through choosing methods and products that have lower impacts and advocating for solutions that reduce energy consumption or the cost of operations and maintenance.

A few months ago I travelled to Kelowna to participate in a Mentoring session titled, “Careers that Change the World”.  I felt a little out of place – I’m a City Engineer and sustainability evangelist in a small town in rural BC. When most people think of changing the world, I’m sure they conjure up images of feeding starving children or designing a vaccine for AIDS. My opinion is that the actions that are going to save our world in the future are those that focus on the local and regional resilience of a group of people. Bringing context to issues like the Deepwater Horizon Oil Spill to a mountain community in British Columbia is an imperative for sustainability and resilience. Knowledge is power and feeds change. The imperative to change is becoming clear – my children are likely to see the end of abundant oil, and if you understand what that means for the lifestyle we have become accustomed to, it should prompt one of two responses. We either need to decarbonize and return to a simpler way of life with a contraction of growth and consumption; or we need to immediately find plentiful, powerful, and portable sources of energy to maintain the lifestyles we love. The lowest risk solution for society to take is the former path – the path most likely to be chosen by politicians or business leaders is the latter. This contradiction is at the heart of much of my writing, the tension between growth and sustainability is evident across all scales of society, from households right through to federal governments and everyone in between.

So I pause, consider what part of the story needs to be told next, and write.

This post was written by Mike Thomas for UrbanWorkbench.com ©2010.

Originally posted as Why I Write

Technorati Tags: British Columbia, Civil Engineering, Creative Class, Design, engineering, environment, Sustainability, urban planning

As a society, (or a species, take your pick), we are terrible at planning and strategising much further than what we are planning to eat for dinner. while Japanese companies plan for world domination in five generations, we are stuck in a revolving door of problems that need immediate attention. But even when we get a crack at addressing one of these problems, there is such a disparity of beliefs and suggestions that it becomes near impossible to make a decision or achieve a consensus between all the stakeholders. Add to the mix the fact that some of the stakeholders have very deep pockets, and it becomes evident that the only decision that is likely to be made is the one that they support (and fund).

Our myopic and blinkered perspective on our current situation leads economists to claim that we’re in a financial crisis; geographers to claim a land use crisis; agro-scientists, a food crisis, water and sanitation engineers, a clean water crisis; biologists to claim an environmental crisis; climatologists, a climate crisis;  engineers, an infrastructure crisis and energy scientists to claim a fossil fuel crisis. Very few of these experts have a global perspective of the issues at hand and how they are all interconnected  at a root level.

The Impact of Humans and Our Inability to Change

While this is not a mainstream concept, I am far from the first to have suggested it. Back in the 70′s , the Club of Rome published a great read called “The Limits to Growth” that I wrote about here. They certainly saw this coming, as have a whole bunch of experts in many varied fields of practice. Unfortunately, people don’t change. At least not without a good reason. Some of those reasons may be social, some may be survival. I spoke about this at a meeting the other day and was met with a mixture of withering or bewildered looks from some hopeful participants who obviously believe that humans will innately do what is best for the species as a whole. To counter this, I would argue that our ability to influence the global climate, resources, land base and water has never been higher and that humans are not equipped with the ability to recognize future peril at a scale larger than that of their immediate community, at most the size of a village, consisting of perhaps 150 people.

Bill Rees gives a talk where he describes the traits that he believes humans use to define themselves above other species, these are the ability to plan, the ability to display empathy, and logical reasoning. But in Bill’s estimation, many of our current crises clearly show that we lack any level of “humane” response on any of these levels. It is almost as though we have far exceeded an ability to coherently respond to the problems we’ve created. Even Obama, the greatest political campaign based on change and a brighter future has floundered once the polls were closed – not because of Obama, but because the resistance to change is extreme. It appeared that there may be the start of a groundswell of change with Obama, however, we soon returned to putting out fires and pretending to plan, instead of using our creative talents to shape the low impact world of the future .

Now there may be corporations who are practicing what looks like “sustainable” business, or individuals who have a small ecological footprint compared with the rest of us, but these are few and far between, and most of these examples still exceed any reasonable estimates of the “carrying capacity” of the earth – even out here in the Kootenays, where many believe t we are on a path to green heaven, the true measures of sustainability, (not just the feel good social ones), score woefully poorly.

Is Failure Inevitable?

The answer to this depends on what you view as failure, and how far away you believe your emergency is.

If you believe in growth as an unretractable paradigm, then you might be in for trouble. Basically, the world has seen massive amounts of growth only as a result of industrialization, before that, the population was mostly stable for centuries, or perhaps millennium. At a 1% rate of population growth, in 100 years the population would have almost tripled; in 1000 years, the population would be over 21,000 times larger. Economic growth, population growth and fossil fuel usage have followed almost parallel trajectories over the past 150 years – this simple calculation shows just how ludicrous the expectation of unrestrained growth is.

If you believe that the society we live in represents a stepping stone to a higher state of existence, where technology actually does make our lives easier and more filled with leisure time, then again, you are probably headed for murky waters. The likely end state of today’s situation is that we will come to understand that this period has been an oil experiment. We have polluted, depleted, exhausted, strip-mined, exploited, deforested, and deepwater-drilled our way into this mess. The earth will likely bounce back, but we have used up the easiest of the fossil fuels, and perhaps as much as half of them. The minerals and rare metals that technology rests on are non-renewable resources, (at least the way we currently use them), and will reach a peak, just like oil.

If you believe that returning to a lower carbon, lower energy state of society is failure, then you might need to re-evaluate your goals. I don’t want to romanticize the past, or glorify a future with less fossil fuel consumption and less overall energy, because  if this is the future, it is not going to be any of the things we’ve come to value as a society, convenient, fast, full of technology and distractions, 24/7 entertainment.

Setting a Path

The long term strategy of any society should be to maintain a reasonable quality of life with no net detrimental impact to the supporting environment. And I’ll lay out the premise that the strategy we’ve selected over the past 100 years appears to be a poor long-term choice – in the short term, we’ve seen countless amazing developments in every industry, including ones that simply didn’t exist 100 years ago. We now have such a huge impact on places we will likely never see in our lives. Factory cities in China, banana plantations in Latin America, grain farmers on the prairies, water users living downstream of us – the practices of modern industrial production, agriculture and society have been a curse as much as a blessing. The quality of life for millions of people around the world has declined as a result of the North American way of life – if the effects were in our own backyard or village, there would be a lot less tolerance for these corporate behaviours.

If we are on a path to failure now, we should be working actively toward a different state. Here are some ideas…

• one that has less reliance on technology (not because technology is inherently bad, but because it inevitably fails, sometimes with catastrophic consequences).
• one that has a fair basis for economic transactions (and speculation is tempered by externally verified auditing).
• one where food production has a larger role to play in society
• one where ethics and values are held in high regard
• one where the true cost of energy is calculated and forms the basis for decisions
• one where social justice and corporate accountability play a role in business and societal decisions

So while we worry about the price of real estate or the current interest rate we are missing the point that the big issues remain unresolved. People have considered solutions to all of the conceivable problems we face, but as a society we’ve done next to nothing with this information – we are still setting ourselves up for failure.

What, barring a catastrophe would make us radically change the way we live to make a measurable change toward real sustainability, (not just the type that is one the car ads)?

This post was written by Mike Thomas for UrbanWorkbench.com ©2010.

Originally posted as Set Up for Failure

Technorati Tags: agriculture, Energy, environment, Fossil fuel, Latin America, peak oil, Population growth, resource depletion, resources, Sustainability, United States

My whole life is surrounded by technology that has been discovered or invented in the past 50 years. I am a product of Generation-X, the epitome of consumerism. I love and want more technology, I crave the latest gadget, I consume therefore I am.

But really, I am a poor example of a consumer, I spent two whole days in Vancouver and bought nothing but food. Technology is useful, but I take much more pleasure in building things by hand or digging in the garden than having the latest. We have internet at home and a couple of computers, but no cable and only a small tv that occasionally gets turned on for some kids videos. We drive modest cars, we infrequently purchase food or drinks from fast food outlets – overall we buck the trends ingrained by years of pressure from advertising, schooling, parents and society in general urging us to be all that we can be.

As I listened to some of the speakers at the Institution of Civil Engineers Convention last week in Vancouver, I was struck at how, even though they were talking “sustainability” in engineering practice, the basis for treating the topic almost always started with the assumption that in general, the typical high level of consumption seen these days is normal and will continue unabated.

Civil Engineers, along with many other professional classes are relied upon by society to respond to challenges with a risk based approach. Too many civil engineers believe that innovation is the only way forward, resulting often in added complexity and consumption of raw materials. Some of the speakers understood this and offered a challenge to design with less impact, and I’d even say, design with less – and to allow that design philosophy permeate through our whole professional lives.

Simplifying your life and simplifying designs is rewarding, the way out of many of our problems is not to rely on technology but to reverse the course we’ve chosen thus far, unwinding the consumption and complexity from our lives.

This post was written by Mike Thomas for UrbanWorkbench.com ©2010.

Originally posted as Simplicity

Technorati Tags: civil engineer, Civil Engineering, Design, engineering, simple, simplicity, simplify, Sustainability

Or “Why I don’t trust BP to clean up anything”

I haven’t dedicated much space here to the ongoing saga going down in Louisiana as BP and the US government fumble to maintain the appearance of control of the situation. I’ll leave the blow-by-blow account of these mishandling to people with more time and patience than myself, I actually find it rather disheartening, so I rarely get past the headlines anyway. I’m a Civil Engineer, I’ve never been on an oil rig, I’ve never even been to Louisiana, but I have studied Coastal Engineering and have a simple understand the physics of pollutant transportation. Basically, oil and water don’t mix, and some oil will get under a boom, and some oil will go over a boom, you can’t expect the boom to magically hold the oil in place while the swell, waves and wind are driving it toward shore.

BP is a drilling company, and like most of their counterparts, it seems that their focus is on the money-making end of the operation, sure safety is important, because no one else is going to help out if something that risks human life goes wrong, but environmentally, it seems that the priority is pretty low. Clean up is an inconvenience, kind of like the collateral damage we saw in the Gulf War, a necessary evil, but not something to focus on. As such, it seems that who ever is in charge of the operation to stop the oil from reaching the shoreline realized that there simply wasn’t enough boom available in the whole world to adequately protect the entire coastline at risk, (oops), or that there weren’t enough people to skillfully manage all of the necessary technical requirements of a proper booming operation. Take a look at the diagram below which has been floating around the internet over the past week in different forms (via: How stuff works).

If you’ve seen the images of useless boom washed up on the shoreline, or whole wetlands inundated with oil, you start to realize that either the technology sucks or the application of the technology sucks. From what I’ve read, it seems that the latter is the case – we seem to be witnessing an inept clean-up operation that will unnecessarily cause millions, if not billions of dollars in hardship for these communities that are affected.

These orange booms, (conveniently coloured for photo ops as well as general visibility I guess) may just be distracting the politicians from making real decisions about the situation – after all the appearance of control is often far from the reality of control.

Emergency Management Scenarios and Planning

Throughout my career I’ve been involved in serious emergency management scenarios, dam breaks, chemical spills, and national emergencies to name a few and in almost all cases, the question that lead to the development of the scenario was, “what if the worst happened”.

In the army we lived by a maxim, (one of many):

Prior Planning Prevents (Piss-)Poor Performance – otherwise known as the five P’s.

Is there any documentation to show that a scenario like this in an emergency management setting had lead to the stockpiling of booming equipment, dispersants, etc, and that an estimate of the manpower required to adequately manage a spill of this magnitude.Had anyone considered the logistics of this? Or were they too busy working out how to dial another percentage point of profit out of the production to worry about planning for an emergency?

Ohh, that’s right, I guess there was nothing to learn from Exxon Valdez.

This post was written by Mike Thomas for UrbanWorkbench.com ©2010.

Originally posted as The five P’s

Technorati Tags: boom, BP, clean up, contamination, Emergency Engineering, emergency management, environment, oil, oil boom, oil spill, planning

Stormwater design is one of the most critical components of urban engineering. Unfortunately in Canada there is no national standard of design principals used by municipalities or approval jurisdictions.

I come from Australia where there is a national standard called Australian Rainfall and Runoff that is published by Engineers Australia. Here in Canada, it seems that the majority of authorities require the rational method as the design method, which is strange, because it is regarded as one of the least accurate methods of design and one of the least sophisticated. So in these days of Civil3D and millimeter accurate design, we are using little more than a guesstimate for rainfall and runoff.

The Rational Method is very popular because it is easy to use and can be set up in a simple spreadsheet program; but the actual application of the method is very complex, something that baffles many designers, both technologists and engineers. There are designers who treat the method in the same way for every job, mainly because they don’t understand hydrology. They just don’t understand how an equation with only 3 terms in it can be used differently for different sites. A steep site behaves very differently compared to a flat site, and the frequency of the storm can impact how we treat the rational method coefficient of runoff or C-Value. In my experience, the best text for use in North America is “Municipal Stormwater Management” by Debo and Reese – and in my assessment of how others use the Rational Method, I defer to this text for guidance.

For reference, here is the most recent Castlegar IDF curve, updated in 2010.

In the past three jobs I’ve held, up until my current role, I have written up guidelines on how to incorporate engineering best practice into the design software being used at these firms. This has ensured consistency in practice and methodology across staff and has ensured that a risk based approach has been followed in drainage design.

In my experience, the rational method should only be used to calculate catchment, approximate in-pipe and open channel flows. It must not, in any circumstances, be used to size detention ponds, I’ll get to that in a future post. Ultimately any stormwater design involving pipes should be analyzing the hydraulic grade line for the design storm, with adequate losses for manholes and catchbasins.

This post was written by Mike Thomas for UrbanWorkbench.com ©2010.

Originally posted as Stormwater Design

Technorati Tags: Castlegar, Castlegar IDF curve, Civil Engineering, Design, drainage, drainage design, engineering, IDF curve, rainfall, rational method, runoff, Stormwater, stormwater design